The present invention relates to a channel bandwidth utilization ratio evaluation method of evaluating a channel bandwidth utilization ratio of each stream, a channel bandwidth utilization ratio evaluating apparatus, and a channel bandwidth utilization ratio evaluation program in a wireless communication system having a MAC (Medium Access Control) layer, which is accompanied by random access, like a VoWLAN (Voice over Wireless LAN). Further, the present invention relates to a wireless communication system employing the channel bandwidth utilization ratio evaluation method.
As the wireless LAN has prevailed, it has become possible to easily construct the wireless communication system for making various kinds of wireless-LAN-based stream communication. For example, it has become possible to simply construct a voice communication system (VoWLAN) for making communication of a wireless-LAN-based voice stream. However, considered from the nature of the VoWLAN, as a rule, the wireless bandwidth (a utilization ratio of the bandwidth) that the voice stream actually utilizes in the VoWLAN tends to vary greatly depending upon system conditions. For this reason, so as to efficiently administer a voice quality in the VoWLAN, it is of importance to grasp an effective use bandwidth of each voice stream and a voice performance of each voice stream.
As a system for evaluating the effective use bandwidth and the voice performance of each voice stream, for example, the system is described in non-patent document 1 of evaluating the maximum connectable voice call number in the wireless LAN using an IEEE802.11. Further, in non-patent document 2, an applicant has proposed the method of evaluating a performance of the wireless LAN having communication errors taken into consideration.
[Non-patent document 1] S. Garg, M. Kappes, “Can I add a VoIP call?” Proc. of IEEE ICC '03, vol. 2, pp. 779-783, 2003.
[Non-patent document 2] H. Pan, S. Sato, K. Kobayashi, “On the Throughput of an IEEE 802.11a Wireless LAN System with Terminals under Heterogeneous Radio Conditions”, Proc. of the 18th ITC, 2003.